19 



Som siip[)lc'ment ti1 Sårs beskrivi-lse skal jeg ;mfoi\^: 



Cornnis incrusterer en mængde sniiui samlpartikler 

 især ved overtladen. Kolonien smalner a f mod sin basis, 

 den er undertiden ved fordybninger paa oversiden afdelt i 

 flere adskilte klumper, der hver repræsentercr et system. 

 Høiden indtil 2 vm.. dianu-tiTc^ii ligeledes iiidtil 2 cm. 



Individernes længde omtr. 9""", bredden oniti-. \. :,'""'. 



Ingestionsaal>ning('n med (J taMuler. 

 Egestionsaalniingen forsynet med en kort analtunge. 



Brancliialsækken, der udgjor halvdelen af hele indivi- 

 dets længde, har alm. 12 stigniarækker med omtr. 18 meget 

 regelmæssige stigmata i hver. 



Dorsallaniina af stigmas længde. 



Ventrikelens overfiade med en utallig niængde smaa 

 halvkugleformige forhøininger (,.areole--j. Dens form er glo- 

 bnløs, ubetydelig høiere end bred. 



Anus udmunder omtr. i lioide med 5te l)ranchialrække 

 ovenfra. 



Postabdomen kort og l)red omtr. af brancliialsækkcns 

 længde og opfyldt af tæt sammenpakkede større og mindre æg. 



Denne art er funden temmelig alm. i Lofoten (Sårs) 

 paa 2t> favnes dyb. 



Botryllidæ. 



Denne fra de ovrige synascidier skarpt afgrændsede 

 familje. omfatter en mængde yderst variable og lidet di- 

 stinkte arter og farvevarieteter. Giard anfører saaledes 

 ikke mindre end 38 l)otrylIus- og botrylloidesformer ira en 

 enkelt lokalitet paa den franske kyst. Lahille tror at kunne 

 fordol)le dette tal, men vil ikke opstille nye former blot 

 støttede paa pigmentets anbringelse og individernes relative 

 dimensioner. Medens denne forfatter fremhæver, ,,at ingen 

 karakter hos denne familje er mere variabel end pigmenta- 

 tionen-', anser Giard denne for ..maaske at give den bedste 

 støtte ved classificationen''. samtidig med at lian dog raaber 

 et varsko: ..himium ne crede colori". Begge anbefaler 

 nndersøgelser af de levende dyr fortsatte gjenneni Lengere 

 tid. Lahille tillige kunstig hyliridation. 



Da jeg selv liar halt anlednin2; til at studere en art: 

 hofryll/is riolarms, (^?)M.-Ed\\'. gjennem længere tid baade i 

 aquarium og paa dens oprindelige levested, skal jeg neden- 

 for anføre nogle af mine iagttagelser angaaende denne arts 

 farvevariationer, koloniernes og systemernes form, udvikling 

 0. s. v. 



Man ser ofte en botryllus-arts systemform beskreven 

 udelukkende som cirknlær en andens som ndelukkende el- 

 liptisk. Dettes form l)eror vistnok i de aller Heste tilfælde 



As a supplement to S:irs's descri|>ti()n. 1 will add the 

 foilowing remarks: 



The cormus is iniTUstcd with nuniliers of little par- 

 ticles of sand, especially on the upper surface. Tiie eolony 

 becomes narrower towards the base. It is sometimes di- 

 vided, ])y depressions on the upper side, into several distinct 

 lumps, each representing a system. The niaximuni height 

 is 2 cm., the diameter the same. 



The length of tiie members is about V)"'", breadth 

 about 1..".""". 



The branchial cu-itice has G denticles. 



Tiie atrial orifice is furnished witli a sliort anal 

 languet. 



The brancJii.il sac. whicli constitutes iialf the length 

 of the niember, has generally 12 rows of stigmata, with 

 about 18 very regular stigmata in each. 



The dorsal laniina is the lengtli of a stigma. 



Tlie surface of the ventricle is covered with innumer- 

 able snnill hemispherical papillæ (,.areolæ-'). The ventricle 

 is globular in shape, slightly liigher than it is bioad. 



The opening of the anus is about on a level with the 

 5th row of branchial stigmata, counting from above. 



The post-abdomen is short and broad, of about the 

 same lengtii as the branchial sac, and is filled with closely- 

 packed, large and small ova. 



This species was rather conimon in Lofoten (Sårs), 

 at a depth of 2() fathoms. 



Botryllidæ. 



This family, which is so distinctly separated from 

 other Synascidiæ. includes a number of exceedingly variable 

 and indistinct species and varieties of colour. Giard, foi- 

 instance, names no fewer tlian 38 Botryllus and Botryl- 

 loides forms from a single locality on the Frencli coast. 

 Lahille is of opinion that he could double this number, 

 but will not establish new forms distinguished only by the 

 mode of pigmentation, and tiic i-clative dimensions of the 

 members. While this latter autlior emphasises the fact 

 that ..no character in the family is more variable than the 

 pigmentation-', Giard considers that it „affords perhaps the 

 best guide in classitication", tliough at tlie same time, he 

 utters the warning : „nimium ne crede colori". Both writers 

 recommend examination of tiie living animal continned for 

 some time. L.-iiiille also artificial liyln-idisation.  



Having iiad tlie op])oi'tnnity of studying one species, 

 BotrijJhift violaceiis, (?) M.-Edw., througliout a lengtiiened pe- 

 riod, lioth in tlic a(iuarium and in its native haunts, I will 

 liere record some of my observations concerning the varie- 

 ties of colour, tile siiape of the colonies and the systems, 

 tlie develojnnent, etc. of tlie species. 



Tlie sj-.ajie of tlio systems in one sjjecies of Botryllus 

 is often described as invariably circular, of another as in- 

 variably eUiptical, lint the shape doubtless depends in most 



A' 



